Firstly, Hi! I'm new here but have kept freshwater fish for a couple of years. I've got a small community tank with Danios and Platys (One male and two female of each species). Recently, the male platy has started attacking one of the females and guarding the other. The one he is guarding is pregnant. The female that is currently pregnant gave birth about 3 weeks ago and there wasn't this level of aggression from the male then. This time around it's crazy. He's actually seeking her out and attacking her. I've now put the male in a breeder tank until his mate gives birth - which should be in the next day or two.
I suppose my question is, will the male settle down once the female gives birth and leave the other female alone (and yes, she's a female. I have one of her babies in another tank) or do I have to remove the male before he kills her?
Any help would be appreciated.

Firstly, Hi! I'm new here but have kept freshwater fish for a couple of years. I've got a small community tank with Danios and Platys (One male and two female of each species). Recently, the male platy has started attacking one of the females and guarding the other. The one he is guarding is pregnant. The female that is currently pregnant gave birth about 3 weeks ago and there wasn't this level of aggression from the male then. This time around it's crazy. He's actually seeking her out and attacking her. I've now put the male in a breeder tank until his mate gives birth - which should be in the next day or two.
I suppose my question is, will the male settle down once the female gives birth and leave the other female alone (and yes, she's a female. I have one of her babies in another tank) or do I have to remove the male before he kills her?
Any help would be appreciated.

Larger tank would help by allowing you to increase the number of females, and maybe give the male other females to hound.(Is what they do ).

Larger tank would help by allowing you to increase the number of females, and maybe give the male other females to hound.(Is what they do ).

I'm currently having a tank and cabinet made and painted. So it's going to take a couple of weeks before it's complete, cycled and ready for some fish. So yeah, you are absolutely right but I don't have the room right now.
Thank you though!

The only things a male platy is interested in protecting are his breeding rights and his own skin. As 1077 stated, more females would spread out the attention. More than likely, the male is sensing an unwillingness to mate on the female's part and he is trying to wear her down. They're real charmers.

The only things a male platy is interested in protecting are his breeding rights and his own skin. As 1077 stated, more females would spread out the attention. More than likely, the male is sensing an unwillingness to mate on the female's part and he is trying to wear her down. They're real charmers.

Ahh that makes sense. The female being attacked has given birth before but she was pregnant when I got her. She's never mated with the male. So the Charm Offensive didn't work and he's trying Shock and Awe now?
Btw - the tank has returned to peace since I've sidelined the male. I'm scared to let him out now.

I had this happen with a pair of gold dust mollies, unfortunately it did not end well. He almost killed one female, and did kill a second, and attacked a third ripping up her dorsal fin. He was the only male in the tank with six females. On very rare occasions you get what I like to call "The Jerk Fish" and I haven't found a way to chill them out. I tried more space, removing him and then moving him back after a few days, more plants and hiding areas, he would just seek out this one female and attack her after she gave birth once and became pregnant a second time. In the end I gave him away and got another male for my tank, which had much better results. I don't like saying that, but that's just what happened to me. lol I hope you have better results when you get more space and another female. Just keep him separated for a while from them and hopefully that will settle him down if you put him in with a new fish. Sometimes that makes them unsure instead of aggressive, and then he may figure out he's got a new girlfriend. I did not try getting him a seventh wife in my case, once a fish does serious damage or kills, it goes to the pet shop. ^^;

You -could- try getting another male of the same size. This can have iffy results though. But usually after they make faces and bug eachother a little bit, they both will settle down and try to breed with the girls. However, it can also have opposite results and the males could fight instead of just spar and chase. I had a male platy that wouldn't leave one female alone. He didn't try to kill her, but he would bug her to no end even with four other girls, so I bought another male and a female with him. They made faces, threatened the other, chased and nipped, but no damage was ever done, and after a few days the other "persistent" male went after -other- girls because he knew he'd lose out otherwise and didn't continuously bother just one, unless she was very receptive.

Thanks Sylverclaws. I had the male isolated for a couple of days which seems to have given the female a bit of time to eat and get some strength back. The male is still harassing her, but now it's just low level sexual harassment rather than Class A Felony behaviour. Can't wait for the new tank to be ready. There will be LOTS of hiding spots in the new tank.